1. Field of the Invention
Embodiments of the invention generally relate to methods and apparatus for converting offshore structures between a concentrated load configuration and a distributed load configuration.
2. Description of the Related Art
Offshore structures are designed using either a concentrated load configuration or a distributed load configuration. Concentrated load offshore structures are most effectively used in applications where the seabed has a high bearing capacity soil to support the concentrated point loads or where soil layers below seabed provide sufficient support after structure penetrating the seabed. A concentrated load offshore structure may not be properly supported if the concentrated point loads are inserted into a low bearing capacity soil. Distributed load offshore structures, however, are most effectively used where the seabed has a low bearing capacity soil. The loads are distributed across the surface of the low bearing capacity soil using a supporting mat structure. Conversely, a distributed load offshore structure may not be the most efficient structure for use in high capacity bearing soil applications when compared to a concentrated load design, due to the additional expense and size of building the supporting mat structure. An operator involved with projects in both high bearing and low bearing capacity type soils must invest in two separate offshore structure designs to effectively and efficiently handle both applications.
There is a need, therefore, for offshore structures that can be converted between a concentrated load configuration and a distributed load configuration.